Cairnfield Muir

This grass- and scrub-grown enclosure, is situated free of tree-cover within the E corner of a coniferous plantation that represents the final phase in the restoration of a large gravel quarry, which lay immediately to the W and was active in the 1980s. The enclosure is slightly oval on plan and measures 32m in diameter from NW to SE by 29.5 transversely overall. A central area, measuring 7m from NNW to SSE by 6m transversely and 0.6m high, is surrounded by a silted ditch up to 8.5m broad and 0.5m deep. This, in turn, is enclosed within an external bank up to 9m thick and 0.6m high, with a crest that appears broadest on the SE. The central area has been disturbed and exhibits traces of a recent excavation up to 0.4m deep, while the ditch is continuous and reveals no sign of a causeway, although it is shallower on the E than on the W. It has been partly infilled on the S with grass-grown dumps of earth, within which is a rectangular pit measuring 2.4m from NW to SE by 1.9m transversely and 0.6m deep. The outer bank, which is also unbroken, has been slighted by arable cultivation on the E and by forestry ploughing on the S and W. Small spreads of field cleared stone are situated in the ditch on the WSW and at the foot of the bank on the NE.

The enclosure, which may have been orientated from NW to SE, has a superficial resemblance to a henge, but it does not belong to the class in a conventional sense. Its general circularity, but not its dimensions, are replicated in the smaller enclosures at Nether Towie (NJ41SW 41) and Tuach Hill (NJ71NE 27), both in Aberdeenshire, while it also has an affinity with the surviving member of the three ‘Laws of Logie’ at Glen Wood (NO66SE 2), Angus. Neither Nether Towie nor Glen Wood have been excavated, but the interior of Tuach Hill has been investigated on two occasions (Stuart 1856; Coles 1901; Bradley and Clarke 2016). This confirmed its origin in the Early Bronze Age, but charcoal sealed below the bank created from the upcast of the surrounding ditch indicated that its central area cannot have been enclosed with the introduction of both the ditch and the central bank until the Late Bronze Age. Such complexity in the evolution of these earthworks may illuminate those monuments where there is a causeway across the ditch, but no break in the bank, as at Achilty (NH45NW 1), Conon Bridge (NH55NW 1) and Culbokie (NH55NE 5), all in Highland, or where a causeway may have been removed. Bradley (2011) has also invited comparison between such monuments and Irish ring barrows.

This monument, which was excavated under the direction of Sir Henry Dryden, is the 'circular trench' described at the beginning of Brodie's article.

Visited by HES, Survey and Recording (ATW, AMcC, KLG), 12 November 2018.

HES surveyed Cairnfield Muir henge with plane-table and alidade on 12 November 2018 at a scale of 1:100. GNSS data was also collected to record survey control and a section across the site. The resultant plan and section were redrawn in vector graphics software.